School, Remote control

Remote.java
-----------
import java.util.Arrays;

public class Remote {
    private String[] channels;

    public Remote(int size) {
        channels = new String[size];
        for (int i = 0; i < channels.length; i++) {
            channels[i] = "";
        }
    }

    public boolean addChannel(String name, int index) {
        if (index < channels.length && channels[index].length() == 0) {
            channels[index] = name;
            return true;
        }

        return false;
    }

    public int find(String name) {
        // -1 if not found
        for (int i = 0; i < channels.length; i++) {
            if (channels[i].equals(name)) {
                return (i + 1);
            }
        }

        return -1;
    }

    public void remove(String name) {
        int index = find(name);
        if (index != -1) {
            remove(index);
        }
    }

    public void remove(int index) {
        channels[index - 1] = "";
    }

    public void sortByName() {
        Arrays.sort(channels);
    }

    public void move(int index1, int index2) {
        String tmp = channels[index1];
        channels[index1] = channels[index2];
        channels[index2] = tmp;
    }

    @Override
    public String toString() {
        String list = "";
        for (int i = 0; i < channels.length; i += 1) {
            list += (i + 1) + " : " + channels[i] + "\n";
        }
        return list;
    }

}

Tester.java
-----------
public class Tester {

    public static void main(String[] args) {
        Remote myRemote = new Remote(10);
        myRemote.addChannel("MBC 4", 6);
        myRemote.addChannel("zee", 1);

        System.out.println(myRemote);

        myRemote.sortByName();
        System.out.println(myRemote);

    }

}